Automatic mining apparatus



Oct 1963 J. w. HEIMASTER ETAL 3,103,739

AUTOMATIC MINING APPARATUS Filed May 27, 1958 s Sheets-Sheet 1 90-250v. D.C.

INVENTORS JOHN w. HEIMASTER FRANK w. JENKINS N LOUIS J. ROGERS S3 WWW/85H E I A TTORNEV Z J. w. HEIMASTER ETAL 3,108,789

AUTOMATIC MINING APPARATUS Oct. 29, 1963 Filed May 27, 1958 3 Sheets-Sheet 2 06 OmN Om INVENTORS 'JOHN W. HEIMASTER FRANK W. JENKINS LOUIS Jv ROGERS A T TORNEV Oct 1963 J. w. HEIMASTER ETAL AUTOMATIC MINING APPARATUS 3 Sheets-Sheet 3 .fiq I Filed May 27, 1958 FLEXIBLE COUPLINGS GEARED SPEED REDUCTION QACK SCREW TILT MOTOR TRUNNION AXIS ATTACHMENT TO MAIN FRAME MAIN FRAME /N 1 5 N TORS W. HEIMASTER FRANK W. JENKINS LOUIS J. ROGERS QWMMM y A TTORNEV United States Patent 3,108,789 AUTOMATHC MINING APPAllATUd John W. Heimaster, Charleston, Frank W. Jenkins, South Charleston, and Louis J. Rogers, Nitro, W. Va, as-

signors to Union Carbide Corporation, a corporation of New York Filed May 27, 1953, Ser; No. 738,698

2 Claims. (Cl. 262-26} This invention relates to apparatus for automatically mining earth materials and more particularly to means for automatically assuring that a mining machine remains in, i.e., does not depart materially from, selected earth strata being mined thereby.

It will be understood by those skilled in the art that coal in situ usually comprises a number of adjacent layers or stratums, i.e., strata varying in relative hardness and composition. Such strata of coal generally are located between layers of relatively inorganic material, such as sandstone, clay, slate, mud, etc. As used hereinafter the term stratum refers to an individual layer of earth material either within the strata of coal being mined or a layer adjacent thereto.

According to the invention there is provided an apparatus for automatically steering a strata mining machine provided with a pivoted head having a front rotary cutter. The machine is steered to follow a course that keeps such machine in the strata being mined thereby, by automatically tilting such head up and down so that it hunts automatically above and below a reference plane that is substantially parallel to the surfaces of such strata as the machine progresses in the general direction or" such references. Such tilting is brought about in response to changes in the relative hardness between selected adjacent strata encountered by such front rotary cutter, by alternating the direction of such head to make adjacent dihedral angles with such plane in response to such changes in hardness. The head is normally tilted to make a dihedral angle with one side of such plane until the cutter encounters such change in hardness. When this happens the head is automatically tilted to make an adjacent dihedral angle with the opposite side of such plane. Such alternate tilts continue to keep the course of the machine generally parallel to such plane and within the strata being mined by the machine as the mining opera tion progresses.

In one modification of the invention the head is normally directed upwardly or downwardly to eventually cause said cutter to contact a harder stratum above or below the strata being mined. Upon contact of such cutter therewith the head is tilted away from such stratum until the cutter is out or" contact with it.

In another modification a stratum within the strata being mined is used for contact of the cutter to control the tilting operation of the head.

In the mining process described in US. Patent 2,699,- 328, it was necessary for an operator continuously to observe received signals picked up by an earth strata cutting indicator, such as described in US. Patents 2,620,386 and 2,752,591 and to manually adjust the steering means of the mining machine, so that the machine mined only the selected strata. Such constant observation and correction is very burdensome.

It is an object of this invention to relieve the operator of such burden, and by making correctional adjustments automatically in response to signals from the earth strata cutting indicator, or similar device for determining the position of the mining machine with respect to an extremity of the stratum being mined.

This is accomplished by the provision of the combination of means for normally steering the machine toward a selected stratum adjacent the selected earth strata being 3,108,789 Patented Oct. 29, 1963 mined by said machine.- A cutter at the front of the machine is responsiveto the approach of the mining machine toward such stratum adjacent the selected earth FIG. 1 is a diagrammatic view of an automatic mining system illustrating the invention;

FIG. 2 is a wiring diagram of the automatic controller;

FIG. 3 is an elevational view showing the mounting of a photoconductive cell to the screen of a cathode ray polar coordinate indicator;

FIG. 4 is a diagrammatic view of an alternative form of the invention;

FlG. 5 is a perspective View of still another form of the invention; and

FIG. 6 is a view partly in elevation and partly in section showing the cutter head tilting means.

As shown in FIG. 1, mining machine 25 comprises a mobile body 26 and a boring section 27 pivotally associated with the front of said body to pivot around a horizontal transverse aXis, so that pivotal motion of the boring section about such axis will cause the path cut by the machine to climb or descend, as desired. A steering "rotor 28 is provided to cause such pivotal motion. The cutter drive gear housing 5% is supported by the main frame so in trunnion bearings 61. The motor 28, driving a jackscrew 62 through flexible couplings 63 and a geared speed reduction 64, causes the-cutter assembly 27 to pivot about the trunnion axis 65.

One or more or" the boring cutter heads 12, FIG. 1, is provided with an earth strata cutting pick-up 13 which transmits signals by suitable means including-a cable 14 to the screen of a cathode ray polar-coordinate indicator 15, as described in the aforesaid U.S. Patents 2,620,386 and 2,752,591. 7

Attached to the screen of the cathode 'ray indicator is a photoconductive cell 16, in such a position that the active area of the photoconductive cell does not come in contact with the normal signal shown on the screen of the indicator when the machine is mining in the selected stratum. However, the cell is positioned so that any cause light tofall upon the active face of the photoconductive cell. This photoeonductive cell is connected by suitable circuit means including conductors l7 and'l8t0 terminals P and C of an automatic controller 19.

A wiringdiagram of 'automatiecontroller 19" is shownin FIG. 2. V and V are conventional triodes and A and B are conventional double pole, double throw relays. The potential of the grid of triode V is adjusted (with a darkened photocond'uctive cell connected to terminals P and C) by means of'yariable resistor R such that the grid is slightly negative with respect to the cathode. The plate potential is then adjusted by means of tap T until the movable armature of relay A is held against its solenoid.

The potential of the grid of triode V is adjusted (with the contacts of relay A and relay B in the position shown in FIG. 2) suchthat it is slightly negative with respect to the cathode. This also chargescapacitor 0,. The plate potential is adjusted (with the contacts of relay B temporarily by-passed) by means of tap T until the movable armature of relay B is held against its solenoid. With the by-pass removed from the contacts of relay B, a cycle is now set up, in which relay B is alternately energized and de-energized, the period of each phase of the cycle depending upon the size of capacitor C the position of the sliders on R; and R and the location of taps T and T, on resistor R The position of taps T and T may be at any convenient spot. Terminals 1 and 6 are provided for future interlocking circuits. 7

As an operating example, photoconductive cell to, FIG. 1, is connected to terminals P and C of the automatic controller, by means of conductors 17 and 18. Terminals 2 and 3 and terminals 4 and 5 are connected into the actuating circuits of a mechanically interlocked reversing magnetic motor controller 2%, by means of conductors 21, 22, 23, and 24, respectively, such that closing of the relay contacts associated with terminals 2 and 3 will cause the motor controller to steer the mining machine downward, and closing of the relay contacts associated with terminals 4 and 5 'will cause the motor controller to steer the machine upward. The mechanical interlock in the motor controller avoids the possibility of damage in the event that both sets of relay contacts should be closed at the same time.

FIG. 3 shows an enlarged 'view of a cathode ray polarcoordinate indicator 15 with a photoconductive cell 16 mounted near the top of the screen of the indicator, and outside of the lighted circle on the screen which normally appears when the mining machine is mining in the desired stratum. Thus, if the machine should depart from such stratum, and cut into the material above it, a lighted patch or eart signal will appear at the top of the screen. (See US. Patent 2,620,386.) Such lighted patch or earth signal will affect the photoconductive cell 16, causing a decrease in its resistance. This decrease in resistance will cause the potential of the grid of triode V (FIG. 2) to become more negative, and triode V will cease to conduct. Relay A will then release its armature, causing the contacts associated with terminals 2 and 3 to close, causing the magnetic motor controller 20 to steer the machine downwards. Capacitor C will maintain this more negative potential on the grid of triode V between appearances of the patch of light, which will reappear about once each second as long as the machine is in contact with foreign material. As soon as the machine has returned to the desired stratum, the patch of light will cease to appear, and relay A will return to its normal position.

While relay A is in its abnormal state, the connection between conductors 8 and 9 is broken, causing the grid of triode V to become and remain positive with respect to its cathode. This allows triode V to conduct, and the solenoid of relay B attracts and holds its armature, opening the contacts associated with terminals 4 and 5, thus causing the magnetic motor controller 21 to cease steering the machine upward if it should happen to be so doing.

When relay A returns to its normal state, the connection between conductors a; and 9 is restored, and the time cycle of alternate opening and closing of the contacts of relay B resumes. This action of the contact on relay B associated with terminals 4 and 5 causes the magnetic motor controller 20 to incrementally steer the mining machine upward, until it enters the foreign material above the desired stratum, when the photoconduotive cell causes the whole operation to repeat.

It may be seen that the circuit of triode V constitutes a relaxation oscillator which periodically energizes its plate circuit to cause incremental motion of the cutter in a given direction from a reference position; and trode V is a control tube operated by an earth signal pickup device which is normally conducting and maintains the circuit of triode V through the contacts of relay A. When an earth signal is received by the pick-up device, the tube no longer conducts, whereby triode V no longer causes motion of the cutter head and triode V causes In the event that it is not desirable to use the cathode ray polar-coordinate indicator, such as might occur when space is limited, a properly rectified signal from an earth cutting pick-up, such as described in US. Patent 2,752,591, can be applied directly to the automatic controller, in the place of the photoconductive cell.

the amplitude of the output of the linear transducer 30 (an internal part of pick-up 13, FIG. 1). Such pick-up is described in US. Patent 2,752,591.

The output of the transducer 30 is rectified by a full wave rectifier 31, which is connected by suitable means including conductors 33 and 34 to terminals P and C of the automatic controller 19 in such a manner that an in-. crease in the output voltage of the rectifier 31 causes the grid of triode V to become more negative. This produces the same effect in the controller as a decrease in the resistance of the photoconductive cell 16, FIG. 1.

The invention also may be usedin connection with the.

automatic course controller described in US. Patent 2,761,666. In such a case, the motor 28, FIG. 1, instead of being mounted on the mining machine, would be mounted so as to turn the shaft of tilt control potentiometer 53, shown in FIG. 4 of US. Patent 2,761,666. FIG. 5 shows a fragmentary view of the motor 28 connected to the shaft of tilt control potentiometer 53. The remainder of the system would be as shown in FIG. 4 of US. Patent 2,761,666.

What is claimed is:

1. Automatic mining apparatus comprising the combination of a bore mining machine having a mobile body provided with a head connected thereto by a horizontal shaft, power means for tilting said head about said axis to steer said machine upwardly and downwardly with respect to a reference plane parallel to strata being mined by the machine, said head having rotary cutting means for mining selected strata as the machine moves forwardly in its course therein, said cutting means being provided with a pick-up that is sensitive to the relative hardness of such strata, a cathode ray polar-coordinate indicator having a screen connected to receive signals transmitted by said pick-up in response to the relative hardness of the strata being scanned by such pick-up, a photoconductive cell operatively associated with said screen to view only select ed signals, an automatic controller operatively associated with said cell, and a magnetic motor controller operatively I associated with said automatic controller and with said power means for tilting said head, whereby as long as such cell fails to see the selected part of such signal the automatic controller operates said magnetic motor conmining operation of the machine progresses.

2. Automatic mining apparatus comprising a mining machine having a mobile body provided with a head connected thereto by a horizontal shaft, power means for tilting said head about the axis of said machine to steer said machine upwardly and downwardly with respect to a reference plane substantially parallel to strata being mined As shown in f FIG. 4, iron core 29 moves axially in response to the I vibrations of the cutting tooth 32 causing changes in by the machine, said head having rotary cutting means for mining selected strata as the machine moves forward-1y in its course therein, said cutting means being provided with a pick-up that is sensitive to the relative hardness of such strata which produces an eart signal when the cutter departs from said strata, an automatic controller operatively associated with said pick-up, and a magnetic motor controller operatively associated with said automatic controller and with said power means for tilting the head, wherein the automatic controller comprises first means including a relaxation oscillator for incrementally increasing the angle of tilt of said cutter head in a desired direction from the reference plane at a predetermined rate, and second means for interrupting the function of said first named means and driving said cutter head in the opposite direction from the reference plane upon receipt of an earth signal from said pick-up means, the driving of the cutter head by said second means continuing as long as said earth signal is received, the first means resuming control of the cutter head driving means when said cart signal ceases.

References Cited in the file of this patent UNITED STATES PATENTS 2,620,386 Alspaugh et al. Dec. 2, 1952 2,699,328 Alspaugh et a1 Jan. 11, 1955 2,761,666 Heimaster et al. Sept. 4, 1956 2,826,402 Alspaugh et a1 Mar. 11, 1958 

2. AUTOMATIC MINING APPARATUS COMPRISING A MINING MACHINE HAVING A MOBILE BODY PROVIDED WITH A HEAD CONNECTED THERETO BY A HORIZONTAL SHAFT, POWER MEANS FOR TILTING SAID HEAD ABOUT THE AXIS OF SAID MACHINE TO STEER SAID MACHINE UPWARDLY AND DOWNWARDLY WITH RESPECT TO A REFERENCE PLANE SUBSTANTIALLY PARALLEL TO STRATA BEING MINED BY THE MACHINE, SAID HEAD HAVING ROTARY CUTTING MEANS FOR MINING SELECTED STRATA AS THE MACHINE MOVES FORWARDLY IN ITS COURSE THEREIN, SAID CUTTING MEANS BEING PROVIDED WITH A PICK-UP THAT IS SENSITIVE TO THE RELATIVE HARDNESS OF SUCH STRATA WHICH PRODUCES AN ''EARTH'' SIGNAL WHEN THE CUTTER DEPARTS FROM SAID STRATA, AN AUTOMATIC CONTROLLER OPERATIVELY ASSOCIATED WITH SAID PICK-UP, AND A MAGNETIC MOTOR CONTROLLER OPERATIVELY ASSOCIATED WITH SAID AUTOMATIC CONTROLLER AND WITH SAID POWER MEANS FOR TILTING THE HEAD, WHEREIN THE AUTOMATIC CONTROLLER COMPRISES FIRST MEANS INCLUDING A RELAXATION OSCILLATOR FOR INCREMENTALLY INCREASING THE ANGLE OF TILT OF SAID CUTTER HEAD IN A DESIRED DIRECTION FROM THE REFERENCE PLANE AT A PREDETERMINED RATE, AND SECOND MEANS FOR INTERRUPTING THE FUNCTION OF SAID FIRST NAMED MEANS DRIVING SAID CUTTER HEAD IN THE OPPOSITE DIRECTION FROM THE REFERENCE PLANE UPON RECEIPT OF AN ''EARTH'' SIGNAL FROM SAID PICK-UP MEANS, THE DRIVING OF THE CUTTER HEAD BY SAID SECOND MEANS CONTINUING AS LONG AS SAID EARTH SIGNAL IS RECEIVED, THE FIRST MEANS RESUMING CONTROL OF THE CUTTER HEAD DRIVING MEANS WHEN SAID ''EARTH'' SIGNAL CEASES. 